Tech Support Document
Thunder Support Document

Humidity and Temperature Chart Recorder Calibration

Chart Recorder.

Figure 2.1

Calibration article (DUT) Humidity and temperature chart recorder, adjustable chart speed from 24-hour, 7 day or 30-day chart. Before calibration install a fresh 24-hour chart if available, select 24-hour chart speed.

Insert the Temp Probe Through the Access Port.

Figure 2.2

Connect the RH/Temp probe to an extension cable if available to allow access to the test chamber. Seal the opening with the white foam access plug. Connect power supply to the chart recorder.

Put the Probe in the Manifold.

Figure 2.3

Position the RH/Temp probe into the manifold fixture with the 2500 chamber temperature sensor. Close the 2500 chamber door.

Set the Speed.

Figure 2.4

Adjust the chart recorder chart speed to 1 day or 24-hour chart speed if adjustable. Apply power to the chart recorder.

Click on Profile and select New Profile.

Figure 2.5

Review the ControLog® Manual if you are not familiar with this software. Open ControLog® software; under the Profile menu select New Profile.

Click the First Cell and Type 20.

Figure 2.6

Click once on the cell of any value needing a change. It is usually best to start at the upper leftmost cell. For this automatic profile calibration we will use 20.0 %RH as the first test point.

Enter the Test Points.

Figure 2.7

The test points selected will be 20%, 50% & 80% returning to 20 %RH, the test temperature has been entered as 23.0 °C, a flow rate of 20 SLPM, you should always run the 2500 at the maximum flow rate of 20 SLPM for best uniformity of the test chamber. The ramp time entered is 0; we want the 2500 to reach the set point as fast as possible. The soak time for the test point will be 2 hours or 120 minutes. This time can be reduced based on the response time of the DUT. We have selected NO for the assured soak conditions; the 2500 will stabilize as close as possible to the test point as selected.

Click the Profile Menu and Select Save Profile.

Figure 2.8

Select Save Profile under the Profile menu. The profile as designed can be reused or revised for similar auto profile calibrations.

Click the Run Menu and Select Auto Profile.

Figure 2.9

Select Auto Profile under the Run menu from the tool bar, the Auto Profile insert will be displayed with the first set point highlighted, click OK the 2500 will start at the first test point of 20.0 %RH at a test temperature of 23 °C.

The Set Points Are Displayed.

Figure 2.10

The 2500 run screen will display the set points as programmed from ControLog® Auto Profile.

Actual Readings Are Displayed, 20 %RH and 23 C.

Figure 2.11

The 2500 display screen after 90 minutes displays a stable reading at 20 %RH at the test temperature of 23 °C.

20 %RH is Displayed.

Figure 2.12

The DUT RH/Temp recorder is shown with a displayed output of 20 at 20.0 %RH, you should monitor the calibration to be sure the displayed output agrees with the trace on the chart record.

23 C is Displayed.

Figure 2.13

The DUT RH/Temp recorder is shown with the displayed output for temperature at test temp of 23 °C.

A Stable Reading is Displayed of 50 %RH.

Figure 2.14

The 2500 display screen is shown with the set point change to 50 %RH after 2 hours.

49 %RH is Displayed.

Figure 2.15

The DUT RH/Temp recorder is shown with the displayed output of 49% at the 50.0 %RH set point.

Graph at 20, 50 and 80 %RH.

Figure 2.16

After 8 hours of Auto profile calibration the ControLog® graph displays the 4 point profile from 20% RH to 80% RH with a final point at 20% RH. The ControLog® graph confirms the stability and time duration of the Auto profile. The file should be saved with appropriate serial number or file name for the RH/Temp recorder.

Chart Shows Start at 20 %RH and End at 80 %RH.

Figure 2.17

The RH/Temp chart record can be compared to the 2500 ControLog® data for error and test stability, the calibration as performed on this instrument was within the manufacturers tolerance. The chart record as prepared should be scanned or photographed for file history on this instrument.

Click here to continue with the next calibration session.

Please contact should you have questions or problems using the procedure. We always appreciate your comments and feedback.

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